package com.qcq.wecheck.util;

import org.apache.commons.lang3.StringUtils;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

/**
 * @author O
 * @date 2018/9/15
 */
public class AesUtils {


	private static final String ENCODE_RULES = "fendo";

	/**
	 * 加密
	 * 1.构造密钥生成器
	 * 2.根据ecnodeRules规则初始化密钥生成器
	 * 3.产生密钥
	 * 4.创建和初始化密码器
	 * 5.内容加密
	 * 6.返回字符串
	 */
	public static String AesEncode(String content) {
		try {
			//1.构造密钥生成器，指定为AES算法,不区分大小写
			KeyGenerator keygen = KeyGenerator.getInstance("AES");
			//2.根据ecnodeRules规则初始化密钥生成器
			//生成一个128位的随机源,根据传入的字节数组
			SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
			random.setSeed(ENCODE_RULES.getBytes());
			keygen.init(128, random);
			//3.产生原始对称密钥
			SecretKey originalKey = keygen.generateKey();
			//4.获得原始对称密钥的字节数组
			byte[] raw = originalKey.getEncoded();
			//5.根据字节数组生成AES密钥
			SecretKey key = new SecretKeySpec(raw, "AES");
			//6.根据指定算法AES自成密码器
			Cipher cipher = Cipher.getInstance("AES");
			//7.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密解密(Decrypt_mode)操作，第二个参数为使用的KEY
			cipher.init(Cipher.ENCRYPT_MODE, key);
			//8.获取加密内容的字节数组(这里要设置为utf-8)不然内容中如果有中文和英文混合中文就会解密为乱码
			byte[] byteEncode = content.getBytes("utf-8");
			//9.根据密码器的初始化方式--加密：将数据加密
			byte[] byteAes = cipher.doFinal(byteEncode);
			//10.将加密后的数据转换为字符串
			//这里用Base64Encoder中会找不到包
			//解决办法：
			//在项目的Build path中先移除JRE System Library，再添加库JRE System Library，重新编译后就一切正常了。
			String aesEncode = new String(new BASE64Encoder().encode(byteAes));
			//11.将字符串返回
			return aesEncode;
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		//如果有错就返加nulll
		return null;
	}


	/**
	 * AES加密
	 *
	 * @param content    待加密的内容
	 * @param encryptKey 加密密钥
	 * @return 加密后的byte[]
	 * @throws Exception
	 */
	public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		kgen.init(128, new SecureRandom(encryptKey.getBytes()));

		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));

		return cipher.doFinal(content.getBytes("utf-8"));
	}

	/**
	 * 解密
	 * 解密过程：
	 * 1.同加密1-4步
	 * 2.将加密后的字符串反纺成byte[]数组
	 * 3.将加密内容解密
	 */
	public static String AESDecode(String content) {
		try {
			//1.构造密钥生成器，指定为AES算法,不区分大小写
			KeyGenerator keygen = KeyGenerator.getInstance("AES");
			//2.根据ecnodeRules规则初始化密钥生成器
			//生成一个128位的随机源,根据传入的字节数组
			SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
			random.setSeed(ENCODE_RULES.getBytes());
			keygen.init(128, random);
			//3.产生原始对称密钥
			SecretKey original_key = keygen.generateKey();
			//4.获得原始对称密钥的字节数组
			byte[] raw = original_key.getEncoded();
			//5.根据字节数组生成AES密钥
			SecretKey key = new SecretKeySpec(raw, "AES");
			//6.根据指定算法AES自成密码器
			Cipher cipher = Cipher.getInstance("AES");
			//7.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密(Decrypt_mode)操作，第二个参数为使用的KEY
			cipher.init(Cipher.DECRYPT_MODE, key);
			//8.将加密并编码后的内容解码成字节数组
			byte[] byte_content = new BASE64Decoder().decodeBuffer(content);
			/*
			 * 解密
			 */
			byte[] byte_decode = cipher.doFinal(byte_content);
			String AES_decode = new String(byte_decode, "utf-8");
			return AES_decode;
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		}
		//如果有错就返加nulll
		return null;
	}


	/**
	 * AES解密
	 *
	 * @param encryptBytes 待解密的byte[]
	 * @param decryptKey   解密密钥
	 * @return 解密后的String
	 * @throws Exception e
	 */
	public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		kgen.init(128, new SecureRandom(decryptKey.getBytes()));

		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
		byte[] decryptBytes = cipher.doFinal(encryptBytes);

		return new String(decryptBytes);
	}

	/**
	 * base 64 加密
	 *
	 * @param bytes 待编码的byte[]
	 * @return 编码后的base 64 code
	 */
	public static String base64Encode(byte[] bytes) {
		return new BASE64Encoder().encode(bytes);
	}

	/**
	 * base 64 解密
	 *
	 * @param base64Code 待解码的base 64 code
	 * @return 解码后的byte[]
	 * @throws Exception e
	 */
	public static byte[] base64Decode(String base64Code) throws Exception {
		return StringUtils.isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
	}

	/**
	 * 将base 64 code AES解密
	 *
	 * @param encryptStr 待解密的base 64 code
	 * @param decryptKey 解密密钥
	 * @return 解密后的string
	 * @throws Exception e
	 */
	public static String aesDecrypt(String encryptStr, String decryptKey) throws Exception {
		return StringUtils.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
	}

	/**
	 * AES加密为base 64 code
	 *
	 * @param content    待加密的内容
	 * @param encryptKey 加密密钥
	 * @return 加密后的base 64 code
	 * @throws Exception e
	 */
	public static String aesEncrypt(String content, String encryptKey) throws Exception {
		return base64Encode(aesEncryptToBytes(content, encryptKey));
	}

	public static void main(String[] args) {
		String[] keys = {
				"", "root"
		};
		System.out.println("key | AesEncode | AESDecode");
		for (String key : keys) {
			System.out.print("key:" + key + " | ");
			String encryptString = AesEncode(key);
			System.out.print(encryptString + " | ");
			String decryptString = AESDecode(encryptString);
			System.out.println(decryptString);
		}
	}
}